The present invention relates to a user setting information management method and management system which manage backup processing of, when a predetermined event occurs, generating a trigger for activating a backup program, reading out user setting information stored in the built-in memory of a portable telephone, saving it in a backup FROM, and when the event which has generated the trigger is canceled, writing the user setting information saved in the FROM in the built-in memory of the portable telephone.
In current portable telephones, information such as a telephone book input by the user is stored in an SRAM (Static Random Access Memory). The SRAM allows free read/write as its feature. However, the SRAM cannot hold data when the backup battery of the portable telephone is dead. If the backup battery is dead, data input by the user is lost, and the user must input them again.
To solve this problem, a flash EEPROM (Electrically Erasable Programmable Read Only Memory) is used for the memory dial of the portable telephone. The flash memory is nonvolatile, enables electrical write/erase, consumes small power, and provides a shorter access time than that of a hard disk. Data is backed up using an FROM which surely holds data. This prevents loss of data caused by a dead backup battery.
Japanese Patent Laid-Open No. 2000-115346 discloses a backup device using an FROM. The backup device disclosed in this reference is directly connected to the data communication connector of a portable telephone via a connector, and receives power from the portable telephone. Under the control of a single-chip microcomputer, the backup device reads out telephone number data from the portable telephone via the connector, stores it in the FROM, and writes telephone number data stored in the FROM into the portable telephone. The portable telephone is notified by a communication means of the end of reading out telephone number data from the portable telephone and writing telephone number data in the portable telephone.
Since the backup device receives power from the portable telephone, the backup device itself can be reduced in size and weight and can be carried together with the portable telephone.
This backup device is convenient when backup operation is normally performed. However, the FROM allows write of data from bit “1” to bit “0”, but does not allow write from bit “0” to bit “1”. Unlike the SRAM, the FROM does not support partial overwrite. To write data in which bits “1” and “0” irregularly appear, like user information data, new data cannot be written in the FROM unless existing data is erased.
Owing to this characteristic of the FROM, the latest data of the SRAM is also lost upon power-off when old backup data in the FROM is erased in order to back up the latest data in the SRAM. In this case, the latest data accumulated in the SRAM is also completely lost together with the old backup data in the FROM. Thus, the data cannot be reconstructed.